Greater prevalence of cancer, especially among the aging generation, and better outcomes of cancer treatment mean that more people are living with the effects of cancer treatment. These specialized healthcare needs can be most effectively addressed by adherence to a survivorship care plan (SCP). The SCP coordinates monitoring for cancer recurrence, management of the effects of treatment, and guidelines for healthy behaviors. However, adherence to the SCP can be challenging for survivors. Furthermore, healthcare providers typically have limited access to information about survivor health and habits. To provide tools that empower survivors to follow their SCP and to give healthcare providers access to more comprehensive health information, we propose to develop a POST-treatment Health Outcomes of Cancer (POSTHOC) platform that incorporates mobile health (mHealth) technologies and up-to-date health IT standards to manage survivor health. POSTHOC leverages mobile and wearable technologies to reinforce the SCP by automatically tracking adherence to physical activity guidelines, assessing and monitoring symptoms through an easily accessible mobile interface, and enabling survivors to provide timely health information. In this way, POSTHOC gives providers tools that extend beyond the walls of the clinic, assimilate and manage patient health outcomes, and empower survivors to manage their ongoing health.